UNIVERSITY OF WESTERN ONTARIO LONDON LONDON Canada
Under certain conditions, military coatings can become soiled or contaminated by oil or waterborne chemical agents, or oilysooty matter from engine exhaust. Protective coatings that are both durable and self-cleaning are desirable, especially for hard to reach locations. Super amphiphobic coatings with high surface roughness and low surface energy maybe appropriate for beading aqueous and oily liquids, however, rough surfaces tend not to be durable, can trap surface contamination, and contact angle hysteresis can increase the tilt angle required for the beaded liquid to roll off of the surface a process by which the rolling liquid drop carries away surface contaminants. For these reasons a smoother surface is preferred. Fluorinated particles can be used for reducing the coatings surface energy but they must be functionalized in order to increase bonding to, and formation of a durable coating. In this report a new approach to fabricate self-cleaning coating surface is investigated, where different types of particles are functionalized in a fluidized bed and dispersed into a commercial polysiloxane coating resin. These coatings were evaluated in regards to their hydrophobicity, oleophobicity and self-cleaning efficiency. The modified paint exhibited similar hydrophobicity, higher oleophobicity, and some improvement in self-cleaning efficiency than the original paint.